A tendency for re-offending in drug-facilitated crime.

The authors present 3 cases that demonstrate a return to DFC following periods of inactivity. The offences occurred in Paris and its suburbs and in each of the cases there were two distinct periods of activity by the offenders with 2, 8 and 22 victims attributed to each of the perpetrators. To 20mg of decontaminated and cut hair, 100 pg/mg of clonazepam-d4 was added as internal standard. Hair specimens were extracted with CH(2)Cl(2)/ether after incubation overnight at 56 degrees C in pH 7.6 buffer. Extractions were performed on blood and urine using Toxi-tube A with 5 ng/mL of clonazepam-d4. The residues were analyzed by LC-ESI-MS/MS. Calibration curves in blood and urine (0.5-500 ng/mL) were prepared by spiking aliquots of blank fluids (r(2)>0.9816 for all drugs). LOD in body fluids ranged 0.5-10 ng/mL. Calibration curves in hair (0.5-100 pg/mg) were prepared by spiking aliquots of blank hair (r(2)>0.9877 for all drugs). LOD in hair ranged 0.5-5 pg/mg. Case #1: Two young women were raped with an interval of approximately 1 year between the incidents. Lorazepam (present, <2 pg/mg) was detected in hair obtained from the first victim, and zolpidem (19 pg/mg) in hair of the second one. The offender was in jail between the two offences. Case #2: The offender approached a total of 8 men and women who were aged over 50 years. The offender was in jail between the two series of respectively 3 and 5 victims. Zopiclone was detected in victims' hair (n=7) at concentrations 13-42 pg/mg. Case #3: The offender stole thousands of Euros using credit cards obtained from 22 different wealthy victims. He employed a cocktail of up to 6 drugs made up of: flunitrazepam, clonazepam, doxylamine, cyamemazine, zolpidem and lorazepam. Drugs were detected in all victims' hair (n=18) at concentrations in the range 1-81 pg/mg for all drugs. Between the two series (of respectively 4 and 16 victims) the offender spent 6 months in jail, and then police spent 6 months looking for him while he was under judiciary control prior to his judgment. Segmental hair analysis permits retrospective information on drug exposure and should be considered in the investigation of drug-facilitated crimes not only to prove single exposure but also when there has been any appreciable delay in samples being obtained for analysis. Indeed, in 56% cases reported in this paper, due to the long time that elapsed between offences and the opportunity to obtain samples for analysis hair analysis was considered the only viable matrix to investigate the possibility of drug involvement in the crimes. Our experience demonstrates that the incidence of re-offending in DFC after a period of inactivity (often due to imprisonment) may be of concern, notably in big cities.